Abstract - Pracownia Elektrochemicznych Źródeł Energii

In this article we present a low temperature method applied to modify the surface of lithium manganese oxide grains’ by using cerium dioxide. In order to determine the structure, size of particles and morphology of the pristine and surface modified LiMn2O4 powders we used several complementary methods: X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and Raman spectroscopy. The galvanostatic charge/discharge tests of the pristine and CeO2 modified LiMn2O4 cathode materials were conducted in the potential range: 3.5 to 4.5 V vs. Li/Li+ at room temperature. High current rates performance has been evaluated by determination of specific discharge capacity at current rates varied from 1 C to 30 C.
Our work demonstrates that surface modification of LiMn2O4 grains’ by using 1%wt. of cerium dioxide admixture improves cycling stability and capacity retention. Pristine LMO reveals 10% capacity loss after 100 cycles when discharged at 1 C, while the sample modified with CeO2 grains reveals only ca. 2% capacity loss.